I have a BU-2 powered sub that needs a transistor/voltage regulator soldered back in place, but I can't seem to find any pictures or a diagram that makes sense. It fell off inside the housing so I still have it, and I'm 99% sure I know where it goes, but I'm not sure which way it goes back in. Does anyone have this sub or know where to find pictures or a good diagram? Here are some pictures of what I'm working with. The three holes for voltage regulator (I think that's what it is) are on the bottom left in the picture, with E on one side and B on the other.